Process for the manufacture of crimped fibers and filaments of linear high molecular weight polymers

ABSTRACT

Fibers and filaments of linear high molecular weight polyesters and copolyesters having a latent three-dimensional crimp are produced by passing the spun filaments after their exit from the spinneret, over a rotating cooled cylinder at a temperature at which they do no longer stick on to the cylinder but are not fully cooled down. The cylinder has a temperature in the range of from 15* to 90*C and rotates at a circumferential speed U of from Vf/50 to Vf-Vf/90, Vf being the draw off speed of the filaments. The filaments are in contact with a surface section of the cylinder the length of which is determined by a contact angle of 10* to 150*.

Elite States Patent 1191 Bauer et al.

PROCESS FOR THE MANUFACTURE OF CRINIPED FIBERS AND FILANIENTS OF LINEARHIGH MOLECULAR WEIGHT POLYNIERS Inventors: Gunther Bauer, Bobingen;Lothar Kramer, Bad Hersfeld; Helrnut Kuhn, Bobingen, all of Germany Farbwerke Hoechst Aktiengesellschaft vormals Meister Lucius & Bruning,Frankfurt/Main, Germany Filed: June 30, 1971 Appl. No.: 158,212

Assignee:

Foreign Application Priority Data July 3, 1970 Germany 2032950 US. Cl264/168, 264/210 F Int. Cl D01d 5/22 Field of Search 264/176 F, 168, 210F References Cited UNlTED STATES PATENTS Neal 264/290 3,458,890 8/19693,480,709 11/1969 Jacob et a1. 264/l76 2 3,499,953 3/1970 Stanley264/210 2 3,511,905 5/1970 Martin 264/210 2 3,520,766 7/1970 Newman264/210 Z 3,547,891 12/1970 Snead et a1. 264/237 3,629,386 12 1971 Knapp264 176 2 FOREIGN PATENTS OR APPLICATICNS 809,273 2/1959 Great Britain264 176 2 1,189,393 4/1970 Great Britain 264 210 Z Primary Examiner layH. Woo Attorney, Agent, or FirmConnolly and Hutz 7] ABSTRACT Fibers andfilaments of linear high molecular weight polyesters and copolyestershaving a latent threedimensional crimp are produced by passing the spunfilaments after their exit from the spinneret, over a rotating cooledcylinder at a temperature at which they do no longer stick on to thecylinder but are not fully cooleddown. The cylinder has a temperature inthe range of from 15 to 90C and rotates at a circumferential speedU offrom V/SOto V -V/90, V, being the draw off speed of the filaments. Thefilaments are in contact with a surface section of the cylinder thelength of which is determined by a contact angle of 10 to 150.

7 Claims, 3 Drawing Figures PATENm w"? 7 20. 4

INVENTORS GUNTER BAUER HELMUT KUHN I TTORNEYS PROCFSS FOR THE MANUFA OFCRIMPED FIBERS AND FILAMENTS OF 51* h HIGH MOLECULAR WEIGHT POLYll/ERSThe present invention relates to a process for the manufacture of fibersand filaments of linear, high molecular weight polyesters andcopolyesters having a latent, three-dimensional crimp and to a devicesuitable for carrying out the said process.

It is especially easy to influence the crystallization and orientationof melt spun filaments of linear, high molecular weight polymers afterthey have left the spinneret and as long as they have not yet completelysolidi fied. When the spun filament is unilaterally quenched or heated,the degree of orientation and crystallization varies over the crosssection of the filament, which can be determined by measuring thedifferent birefringence values on the opposite sides of the filament. Ina later shrinking process the differences in orientation andcrystallization thus produced cause the filament to shrink to differentextentson the opposite sides of its cross section whereby a helical orspiral crimp of the filament is obtained.

It has been proposed to produce such an asymmetric crystallization andorientation by'unilaterally heating the filament (cf. British Patent1,016,100). An analogous effect may be obtained'by unilateral quenching,for example by means of a liquid film on a porous support, into whichfilm the filament immerses with part of its diameter only (cf. FrenchPatent 1,145,727). Furthermore, it is possible to cool freshly spunfilaments on one side by a gas current just below the spinneret (cf.French Patent 1,257,932). A three-dimensional crimp may also be broughtabout with the aid of a cooling body installed in the spinning shaft soas to be in contact with one side only of the filament (cf. FrenchPatent 1,559,751).

It is known that in the manufacture of filaments from high meltingsubstances, for example glass, a quenching below the spinneret by 1,000to 1,500 centigrade sets the curvature produced thereby so that a strongvisible crimp is obtained. To quench the glass filaments, thin coolingrods as well as two air currents directed one against the other are used(cf. British Patent 769,876). This process used for glass filaments isunsuitable in the manufacture of filaments from organic linear polymersof high molecular weight because the considerably smaller temperaturedifference between the plastic and the solid state is not sufficient tostabilize the geometric shape taken at the moment of quenching.Moreover, polyester filaments which have not been drawn after quenching,have too low a tensile strength and a poor elasticity, contrary to glassfilaments.

The known methods permit, with more or less success, the manufacture oflow titre, melt-spun filaments of linear, high molecular weight polymershaving a spiral r helical crimp. With high titres, these methods do notyield filaments with satisfactory crimp.

The known modes of operation are not suitable to produce a sufficientgradient of birefringence over the cross section of the filament becausethe contact between the filament and the cooling device is not intenseand effective enough.

The present invention provides a process and a device for themanufacture of fibers and filaments of high molecular weight polyestersand copolyesters, especially polyethylene terephthalate, which fibersand filaments have a latent three-dimensional crimp and a final titre inthe range of from 4 to 300 dtex. Dtex is the weight of 10,000 m. offilament.

Fibers and filaments of this type are produced by passing the spunfilaments, after they have left the spinneret, over a rotating cooledcylinder having a temperature of from 15 to C, preferably 20 to 40C anda circumferential speed U in the range of from U= V150 to U U V W/90,preferably U= V,/l0 to U= 6V,/1O V; being the draw off speed of the spunfilaments, while being in contact with the cooled cylinder on a surfacesection the length of which is determined by a contact angle of 10 to150, preferably 30 to To carry out the process of the invention a deviceis used comprising a first cooled, driven cylinder, and a second cooleddriven cylinder which can be displaced on a semi-circular orbitpreferably concentric with respect to the jacket of the first cylinderand locked at any point of this orbit, the distance in meters betweenthe centers of the two cylinders being not larger than b =R +R 1 10 cosa in which R is the radius of the first cylinder, R4 is the radius ofthe second cylinder' in meters and 0: indicates the contact angle.

According to a preferred variant of the device of the invention thefirst cooled cylinder has a diameter of 0.3 10 to 20 10 mm, preferably1.7 lO to 4.0 10 mm and the second cylinder has a diameter of 0.3 10 to1 10 mm, preferably 0.3 10 to 0.9 10 mm. The circumferential speed ofthe second cylinder is preferably in the range of from 0 to l 10 m/min,more preferably 0 to 0.9 10 m/min.

The process of the invention yields especially valuable fibers andfilaments from a high molecular weight linear polyester having aspecific viscosity above 0.5, preferably above 0.8, measured with a lpercent by weight solution of the polymer in phenol/tetrachloroethane ina weight ratio of 3 2 2. After drawing, the polyester filaments have afinal titre of 4 to 300 dtex.

The manufacture of the filaments having a latent crimp according to theprocess of the invention is now described with reference to theaccompanying drawing in which FIG. 1 is a side view of the deviceaccording to the invention,

FIG. 2 is a front view of the device and,

FIG. 3 is a cross sectional view of a filament with different zones oforientation and crystallization.

The polyester is melted in known manner with the aid of a melting grateor on an extruder and the melt is passed through a spinneret having sucha number of orifices that the filaments 2, after having left thespinneret 1, lie side by side on cylinder 3 without disturbing eachother, so that they cannot stick together while they travel over thesurface of the cylinder. To this effect the orifices are preferablydisplaced with respect to one another. Their number thus depends on thediameter of the spinneret and the width of the cylinder. Furtherdefinitions are given in the examples.

Cylinder 3 is installed below spinneret 1 at such a distance (a) thatthe spun filaments 2 when striking the surface of cylinder 3 are cooledat a temperature at which they are no longer sticky but at whichorientation and crystallization can still be influenced by quenching. Asthese two conditions do not always agree with one another, the cylindershould have a surface such that a good contact with the filaments isensured as long as they are on the cylinder but that they readily detachwhen leaving it. For this purpose the cylinder preferably has a matchromium plated surface. Distance (a) depends on the titre, the spinningtemperature and the circumferential speed U of cylinder 3 in the mannerdescribed in the paragraph dealing with the influence of the spinningparameters and it can easily be adjusted empirically. It should be assmall as possible.

To adjust the temperature of cylinder 3 a cooling medium is passedthrough which may be either liquid or gaseous. In most cases tap wateror desalted water will be used, which is supplied and withdrawncentrically 7,8.

Cylinder 3 rotates in the direction indicated by the arrow in FIG. I andhas a drive of its own. The circumferential speed U is adjusted to avalue in the range of from U V,/50 to U V,V,/90, preferably U= V/IO toU= 6V,/l0, v being the draw off speed or the spun filaments.

An intense contact of the large cylinder 3 with the spun filaments 2 isbrought about by a smaller cooled and driven cylinder 4. At thebeginning of the spinning operation, small cylinder 4 the diameter ofwhich is preferably in the range of from 0.5 10 to 0.7 10 mm is situatedin position 4a. It can be displaced along a semi-circular orbit c whichis preferably concentric with respect to cylinder 3. After the beginningof spinning it is swung into a position 4. Owing to the fact that it canbe locked at any point of orbit c, contact angle a defined above of thespun filaments can be adjusted on cylinder 3 as desired. In FIG. 1, thecontact angle a is shown as a sector of cylinder 3.

Cylinder 4 preferably has the same mat chromium plated surface as largecylinder 3 and is cooled by a cooling medium supplied and dischargedcentrically 9, l0. Cylinder 4 advantageously has approximately the samesurface temperature as cylinder 3, is driven by its own drive in thedirection of the arrow indicated in FIG. I. In the preferred variant ithas a circumferential speed of to l 10 preferably 0 to 0.9 10 m/min.

Distance [2 between the centers of the two cylinders in meters shouldnot be larger than b=R +R,+l+ l0cosa, R and R, being the respectiveradii of large cylinder 3 and small cylinder 4 in meters and (1representing the contact angle. The distance is defined by the fact thatwith a position of cylinders 3 and 4 with respect to one another with acontact angle a of 90 a distance b which is larger as defined abovecauses the filaments to break. The distance between the two cylindersmay be the larger the closer the direction of the filaments between thetwo cylinders comes to the perpendicular (a 0).

After having left small cylinder 4 the bundle of cooled filaments 5 ispassed over a guide 6 or another deflection roll and wound up or laiddown in a spinning pot without having passed a draw off shaft within alength of 10 to meters as otherwise necessary with coarse filaments,suitably after having been treated with a known antistatic andantiadhesive preparation.

The spinning tow obtained in this manner can be drawn as usual, forexample between drawing elements with the aid of saturated vapor orsuperheated steam, warm water or hot air. It is also possible to heatpart or all of the godets of the intake unit.

The three-dimensional crimp can be released either in the tow or in thecut fibers in the apparatus used in the manufacture of synthetic fibersfor setting the crimp in the stuffing chamber and eliminating too largea shrinkage. The tow (with an advance of about 1 7) or the flock can bepassed, for example, on a conveyor belt through a zone of hot air orsuperheated steam. As in the case of conventional processes for crimpingfibers in the stuffing chamber, the heat treatment is carried out toavoid too large a shrinkage by anticipation, whereby asymmetricallyoriented fibers acquire a spiral crimp.

The heat treatment is carried out at a temperature in the range of fromto 230C, preferably to 160C. For the transmission of heat, air, steam,liquids or heated surfaces may be used.

in the process of the invention the various spinning parametersdecisively influence the properties of the crimped fibers obtained.There must be taken into consideration not only the specific viscosityof the starting material, the number of orifices of the spinneret, theconveyed amount of spinning mass and the draw off speed of filaments,but also the distance a of large cylinder 3 from spinneret 1, thecircumferential speed U of cylinder 3, the contact angle a of the spunfilament around cylinder 3 and the circumferential speed Z of smallcylinder 4.

Influence of the specific viscosity of the starting material A highspecific viscosity of the starting material means a high melt viscosityand simultaneously a higher spinning tension (measured between guide 6and the pull-off godet before the winding up. A higher spinning tensionreduces the danger of sticking of the spun filaments on the cylinder 3and thus permits a reduction of the distance a whereby, on the one hand,the filaments are quenched by cooling cylinder 3 while having a highertemperature so that the difference in temperature between the cooled andthe uncooled side of the filament is greater and, on the other, thefilaments are quenched at a earlier stage of pre-orientation, wherebythe gradient of birefringence over the cross section of the filamentbecomes larger, i.e. a stronger crimp is fonned after release.

In the following Table l are compared the crimping properties of twotypes of filaments spun under identical conditions from two startingmaterials having different specific viscosities (the other parametersnot mentioned are kept constant in this and the following experiments).

The abbreviations used in the table have the following meaning:

K (crimp) l 1 /1,. percent wherein l is the length of a crimped fiberloaded with a preliminary load of 1.8 mg/dtex,

I is the length of the same fiber in a de-crimped state.

The force necessary for de-crimping is determined with the aid of aforce/elongation diagram of the respective fiber type to be tested.

K (residual crimp) I l /l 100 percent 3,832,435 6 wherein Table 2a 1,;is the same length of a crimped fiber loaded with a preliminary load of1.8 mg/dtex as with l, with the I sole difference that fiber R is loadedprior to the if 313 AD 222?;

test for l minute with a load of 0.45 p/dtex and the 5 measurement iscarried out after a subsequent re- 2 2? 3g g? covery of 1 minute, I isthe length of the fiber R in the de-crim'ped state cf 1 a W ..h. a :4...i .H e) 1 o Influence of the draw off speed Table 1 An increase in thedrawoff speed mainly increases the spinning tension whereby, as pointedout above in fixpeNrment K,.(%) R bends/cm connection with the specificviscosity, the distance a y between cooling cylinder 3 and spinneret 1can be re- 1 0.8 42.9 1 0 4 duced and a more pronounced crimp can beproduced 2 0 9s 53 0 34 s 10 4 (cf. Tables 3 and 4).

2. Table 3 m. Exp. final supply of draw off distance draw ratio K K Rbends/ No. titre spinning speed a cm dtex mass g/min m/min mm Influenceo ftlir 'humserardrtri'ces" irriiies siaaerr' Table zsirows martan;fianhi ttmzmiat been With too high a number of orifices in thespinneret asymmetrically quenched according to the process of thedistance between the spun filaments on the cooled the invention have arelatively high degree of preoriencylinder 3 and on the path from thespinneret l to said tation. The degree of preorientation may be furtherincooled cylinder is very small so that the individual filacreased by ahigh draw off speed and a high specific visments may stick togetherowing to vibration of the apcosity of the starting material. By anincreasing degree paratus or a draft, whereby processing troubles ariseas of preorientation, the difference in orientation caused inconventional spinning and drawing processes. by quenching is likewiseincreased, this being desirable. Influence of the conveyance of spinningmass The high degree of preorientation yields filaments Under constantconditions but with a higher amount which can be drawn to a small extentonly. A draw ratio of spinning mass conveyed the titre of the spunfilaof l :4 or there above, as generally used with polyester mentsnaturally increases. filaments, would cause the filaments to break andform With a low titre the spun filaments often come into laps on thedrawing godets. Care should be taken, howcontact with the large cylinderafter they have substan- 40 ever, that the highest possible draw ratiois used as the tially cooled down, since otherwise they do not supportdegree of shrinkage, the difference in shrinkage bethe tension exertedthereon. tween the cooled and the uncooled side of the filaments if toolarge a contact angle a is chosen, filaments of and consequently thecrimp depend thereon. very low titre are cooled down over their entirecross Influence of distance a between spinneret 1 and cooled section sothat crimping is not possible. ylind 3 Under identical conditionsfilaments having different final titres are cooled to a different extentover their cross section. In Table 2 there are indicated the differencesin the birefringence as a measurement for the asymmetry of the spunfilaments with respect to crystallization and orientation in differentsections of their cross section in filaments of two different titres.FIG. 3 of the accompanying drawing illustrates the sections where themeasurements were taken. The final titre is the titre of the filamentsand fibres after drawing and development of the crimp.

lt is obvious mime greateEtheHistance a between spinneret l and cooledcylinder 3, the smaller the difference in the birefringence AD in theopposite sides of the cross section of the filament. The lower thetemperature of the filament at the moment it strikes cooled cylinder 3,which depends on the distance between the spinneret and the cylinder,the smaller the temperature difference in the opposite sides of thefilament after quenching. Hence, the intensity of the crimp diminishes,while the draw ratio possible without breaking the filaments, andconsequently the tensile strength and Table 2 thebending-breaking-stress stability increase (cf. Table Y 4). Therefore,the smallest distance yields the best birefringence l0 Exp, final i 15in i 3rd diff r crimp. In consideration of the above statements, thisNo. g ue smallest distance must be greater with higher titres, ex) 3,5,:232 higher spinning temperatures and a higher circumferential speed U ofcylinder 3 than with a fine titre, a 2 8 fig is? 2-2 v lower spinningtemperature and a slower speed of rotation of cylinder 3. The mostfavorable distance a for the chosen combination of the other parametersis the dis- The influence of the difference in the birefringence tanceat which the filaments just run off cylinder 3 (AD) on the crimp isshown in the following Table 2a). without sticking together or beingentrained.

Table 4 Experiment No. 7 8 9 distance (mm) 400 600 900 tensile strength(p/dtex) 22.7 30.1 39.2 elongation at break 7!) 40.3 39.5 40.2 K ('71)39.3 35.5 33.0 K (/r) 28.4 27.4 24.3 bends/cm 6.4 5.6 4.8chafing-bending turns 960 1360 1500 until break The tensile strength andelongation at break were measured on a Fafegraph fiber breakingapparatus of Messrs. Textechno and the bending-breaking-stress stabilitywas determined on a testing device as described in Chemiefasern, No. 12(1962), page 853 by K.l-l. Grunewald. lnfl uence of the circumferentialspeed U of cylinder 3 The smaller the circumferential speed U ofcylinder 3 with respect to the draw off speed V of the spun filaments,the higher the friction and the lower the degree of orientation of themolecules on the cooled side of the surface. On the other hand, by thefriction a tension is built up towards the large cylinder which resultsin a higher preorientatipn and hence a lower draw ratio.

The above experiments show that with a circumferential speed U ofcylinder 3 of less than V110, fibers Table 6 Exp. circumferential drawfinal tensile elonga- No. speed 2 m/min ratio titre strength tion at(dtex) (p/tex) break Influence of the contact angle a A larger contactangle a of the filaments round cylinder 3 results in a longer residencetime of the filaments on the cooled surface. Hence, a larger portion ofthe cross section of the filament is cooled, the crimp becomes morestable (as the portion causing the crimp is Table 5 Experiment No. 10a10b 1 1 12a 12b pull off V, (m/min) 1000 1000 1000 1000 1000 U (m/min)50 200 270 340 700 final titre (dtex) 51 46 39 34 25 AD 73 60 32 18 4draw ratio 1 1.26 121.39 1:1.64 111.89 112.47 tensile strength (p/tcx) 91 17.0 33.0 34.6 37.1 elongation at break /r) 23.2 31.9 34.6 39.6 38.9K, (91) 69.4 61.5 32.0 28.0 22.3 K (61) 47.7 45.4 25.3 19.8 15.6bends/cm 11 6 10.3 5.6 4.8 2.1 chafing-bending turns until break 7 1301200 2070 2340 are obtained which have a poor tensile strength andabrasion resistance and are, therefore, not very suitable for practicalpurposes. With a circumferential speed.

greater) but the fineness of the bends is a little reduced. Thedifference in birefringence increases with an increasing angle while thedraw ratio decreases to a small higher than 6 V110, fibers having largebends are 0b-- n )dcfincd in Example 1 below tained which are not veryvoluminous and of minor in-' terest only.

When in the spinning process the circumferential The following examplesdescribed fibers and filaments produced with the aid of the device ofthe invention. The indicated titres do not represent limits of theprocess of the invention, fibers and filaments having a speed ofCylinder 315 below 1 above I I finer or larger titre and a more intenselatent threewith a contact angle within the indicated range,considerable spinning difficulties are encountered or uncrimped fibersare obtained. Influence of the circumferential speed 2 of cylinder 4dimensional crimp can also be produced.

The filaments and fibers produced by the process of the invention andhaving medium or large titres have an excellent three-dimensional crimpof good stability. They are very suitable as upholstery filling or forthe manufacture of tufted felt carpets.

EXAMPLE 1 Polyethylene terephthalate having a specific viscosity of1.005, measured with a 1 percent by weight solution of the polymer in a3 2 parts by weight mixture of phe- 1 nol and tetrachloroethane, wasspun as described conveyance of p g mass 245 s/min above through aspinneret having 25 orifices in a line f Speed filaments 000 f28 C d h fn distance a of cylinder (3) at a spinning temperature 0 un er t e oowing f spinneret (1) 450 mm spinning conditions: 5 Contact angle 110circumferential speed U of cylinder (3) 270 m/min circumferential speedZ of cylinder (4) 0.9 m/min radius of cylinder (3) 8.5 cm conveyance ofspinning mass I 240 g/rnin temperature of Cylmder 3) 36 C draw off speedof filaments 550 m/miri distance a of cylinder (3) from s 't l 50g'figgfl c The other conditions were identical with those of Exif g gSpeed U V ample 1. The fibers obtained after drawing in a ratio of f g RZ 1 1.52 and a heat treatment under the conditions of cylinder 4 2.65m/min specified in Example 1 had the following properties: diameter ofcylinder (3) 19 cm diameter of cylinder (4) 7 cm temperature of cylinder(3) 27C temperature of cylinder (4) 27C '"dlvldual dtex tensile strengthp/tex 28 elongation at break D 32.1 crimp K, 42.9 v I residual crimp K 3l .l The tow was drawn in a ratio of 1 1.94 by blowing crimp slflbililysaturated steam onto it between godets having room e temperature and thecrimps in the tow were developed I in the setting tube by means of hotair (300C). The fil- Flee much had been Spun from the same Polymer amemsobtained had the following properties: by a conventional process, i.e.,without the cooled cylinder, with a conveyance of 300 g/min and a drawoff W a v. a speed of 425 m/min and drawn in a ratio of 1 4.03 had thefollowing properties:

individual titre dtex l03 tensile strength p/tex 21.8 30

clon t'o tbre k D 7 38.7

crim? I n a a c 431 individual titre dtex 46.8

residual crimp 34A tensile strength p/tex 30.8

crimp ability 7L6 elongation at break D 64.4

crim stabilit =K K {00 resi ua crimp R o p y l crimp stability 1 35.8bends/cm 4.8

EXAMPLE 2 The above values shown that fibers of high titre spunaccording to the process of the invention have an initial 40 crimp andresidual crimp that are considerably higher than the crimp obtained in aconventional stuffing chamber for two-dimensional crimps.

Polyethylene terephthalate as defined in Example 1 was spun at 285Cthrough a spinneret with 120 orifices in a row. With a conveyed amountof spinning mass of 205 g/min and a draw off speed of 1,800 m/min thefollowing conditions were observed:

EXAMPLE 4 distance a of cylinder (3) from Spinner 150 mm Polyethyleneterephthalate having a specific viscosity circumferential peed U ofcylin er (3) 440 m/mln of 1.05 was spun through a spinneret with 43trilobal orifices at a temperature of 291C. The cooled cylinder 3 hadadiameter of 21 cm. In the present and in all following examplescylinder 4 had a diameter of 70 mm and was kept'at a'temperatuie of 25to 35C.

The remaining conditions such as Z, diameter of cylinders andtemperatures thereof were the same as in Example 1.

After drawing in a ratio of l 1.41 and development of the crimp in themanner described in Example 1, fi-

bers having the following properties were obtained: conveyance ofspinning mass v 126 g/min draw off speed of filaments 1,100 m/min 5distance a of cylinder (3) v from spinneret (I) 250 mm individual titrcdtex 9.0 Contact angle (a) tensile strength p/tex 25.3 circumferentialSpeed U elengenen at break of cylinder (3) 400 m/min p circumferentialspeed Z residual crimp 7r 23.9 of cylinder (4) 0 g r Mammy temperatureof cylinder (3) 30C en s/cm temperature of cylinder (4) 30C coolingmedium tap water EXAMPLE 3 The polyethylene terephthalate used had aspecific The lobed fibers obtained were drawn in a ratio of 1 viscosityof 0.85. The polymer was spun through a plate 5 2.18 and the crimp wasdeveloped as described in Exnozzle having 43 orifices and a diameter of134.5 mm ample l. The fibers obtained had the following properat atemperature of 287C. ties:

Polyethylene terephthalate having a specific viscosity of 1.0 was spunas described in Example 1 under the following conditions:

number of orifices 25 conveyance of spinning mass 240 g/min draw offspeed of filaments 180 m/min' distance a of cylinder (3) from spinneret(1) 310 mm contact angle (a) 1 10 circumferential speed U of cylinder(3) 74 m/min circumferential speed 2 of cylinder (4) 2.7 m/min radius ofcylinder (3) 105 mm temperature of cylinder (3) 25C temperature ofcylinder (4) 25C The fibers were drawn in a ratio of l 3.53 and thecrimp was developed as described in Example 1. The fibers obtained hadthe following properties:

individual titre dtex 198.0 tensile strength p/tex 30.4 elongation atbreak 7L 51.5 crimp K,,- 71 43.2 residual crimp K 71 31.0 crimpstability 71.5 bends/cm 3.8

EXAMPLE 6 A copolyester (as described in DOS 1,495,625 (GermanApplication as laid open to public inspection)) consisting of ethyleneglycol terephthalate units and percent of 2,Z-dimethyl-propanediol-l,3units, calculated on dimethyl terephthalate, and having a specificviscosity of 0.625 was spun under the following conditrons:

spinning temperature 280C number of orifices in spinnerct 120 conveyanceof spinning mass 225 g/min draw off speed of filaments 1.800 m/mindistance a of cylinder (3) from spinneret (l) 450 mm contact angle (a)55 circumferential speed U of cylinder (3) 470 m/min circumferentialspeed Z of cylinder (4) 1.5 m/min radius of cylinder (3) 8.5 cmtemperature of cylinder (3) 32C temperature of cylinder (4) 30C Afterdrawing in a ratio of l 1.58 and development of the crimp in the mannerdescribed in Example 1, fibers having the following properties wereobtained:

individual titre dtex 6.7 tensile strength p/tex 31.1 elongation atbreak 29.6 crimp K 26.6 residual crimp K 18.0 bends/cm 8.0

What is claimed is:

1. A process for the manufacture of filaments of linear high molecularweight polyesters and copolyesters having a latent, three-dimensionalcrimp by asymmetrical cooling and a final titer of from about 4 to 300dtex after drawing, which comprises passing the melt spun filaments,substantially immediately after they have left the spinneret when justcool enough to avoid sticking over a substantially dry smooth rotatingcooled cylindrical zone having a temperature of from 20 to 40C and acircumferential speed U in the range of from U V,/5O to U V,- V,/ with Uranging from about 74 m/min. to 470 m/min., V; being the draw off speedof the spun filaments from the cylindrical zone, whereby the filamentsare in contact with the cylindrical zone on a surface section, thelength of which is determined by a contact angle of 10 to 150.

2. The process of claim 1, wherein the polyester is polyethyleneterephthalate.

3. The process of claim 1, wherein the cooled cylindrical zone rotatesat a circumferential speed 4. The process of claim 1,1wherein thecontact angle determing the length of the filaments in contact with thecooled cylindrical zone is in the range of from 30 to 5. The process ofclaim 1, wherein the polyester has a specific viscosity above 0.5.

6. The process of claim 1,? wherein the polyester has a specificviscosity above 0.8.

7. A process as set forth in claim 1 wherein the circumferential speed Uranges approximately from 200 to 340 m/min.

2. The process of claim 1, wherein the polyester is polyethyleneterephthalate.
 3. The process of claim 1, wherEin the cooled cylindricalzone rotates at a circumferential speed U Vf/10 to U 6Vf/10
 4. Theprocess of claim 1, wherein the contact angle determing the length ofthe filaments in contact with the cooled cylindrical zone is in therange of from 30* to 115*.
 5. The process of claim 1, wherein thepolyester has a specific viscosity above 0.5.
 6. The process of claim 1,wherein the polyester has a specific viscosity above 0.8.
 7. A processas set forth in claim 1 wherein the circumferential speed U rangesapproximately from 200 to 340 m/min.